A kinetic model that fits nicely isothermal and non-isothermal bulk crystallizations of polymers from the melt

作者：Lopez Beceiro Jorge; Gracia Fernandez Carlos; Artiaga Ramon^*

来源：European Polymer Journal, 2013, 49(8): 2233-2246.

DOI：10.1016/j.eurpolymj.2013.04.026

• Crystallization
• Kinetics
• Syndiotactic polypropylene
• Polyamide

A model describing the low temperature solid state phase transformation kinetics observed in a metal organic framework by differential scanning calorimetry (DSC) at several cooling rates is modified so that the reaction rate is now expressed as a function of time and temperature. Thus, when applied to ramp data, the new model exactly matches the former one but, additionally, it allows to explain isothermal data. The new model is tested for primary crystallizations of two polymers from the molten state, using DSC data, cooling ramp experiments at several cooling rates and isothermal experiments. Good fittings were obtained at all the varied experimental conditions with both polymers. The model makes use of three fitting parameters with physical meaning: an upper critical temperature, T-c, an energy barrier, and a reaction-order, n + 1. Additionally, and previously to perform the kinetic fitting, the dependence of the time to the maximum crystallization rate peak on the isothermal temperature was investigated. That dependence was found to follow a simple model which makes use of two parameters related to the limits of the temperature range in which the crystallization may occur. The polymers used in this work were a commercial extruded polyamide and pristine syndiotactic polypropylene.

• 出版日期2013-8